Improvement in taps and dies



UNITED STATES PATENT OEEICE.

GEORGE GRBEL, OF NEW ORLEANS, LOUISIANA.

IMPROVEMENT IN TAPS AND DIES.

Specification forming part of Letters Patent No. 81,162, dated August18, 1868.

To all lwhom it may concern:

Be it known that I7 GEORGE GRBEL, of New Orleans, in the parish ofOrleans and State of Louisiana, have invented new and ImprovedScrew-Outting Dies; and I do hereby declare that the following is afull, clear, and exact description thereof, which will enable othersskilled in the art to make and use the same, reference being had to theaccompanying drawings, forming part of this specification.

Figure l represents a sectional view of my improved screw-die. Fig. 2 isan inner face view of one of the cheeks of thel same. Fig. 3 is asimilar view of the other cheek of the same. Fig. 4 is a plan or topview of the same.

Similar letters of reference indicate corresponding parts.

cheeks the second, fourth, sixth, eighth, &c.,

and many cutting-edges are produced by theprojecting ends of eachportion of thread, and the device will therefore work with lessfriction, and will require less power than the full unbroken thread.

The same invention is applicable to male-die screws for making nuts, inwhich case, also, alternate sections of the cutting-thread are removed.

I claim- As my improvement of screw-cutting dies and taps, whose threadsare divided transversely, so as to present two or more salientcutting-points, omitting every alternate thread, and arranging thosethat remain in alternation, so that the sections of cutting-threadfollowing one another shall successively cut and give shape to oppositesides of the thread in the nut, or on the boltwhich is being threaded ortapped, substantially as described.l

GEORGE GRUBEL.

Witnesses:

F. A. LOEEER, GorrL. BRENNENs'rUHL.

